1. Field of the Invention
The present invention relates to an outer door handle structure for a door, such as a back door and a side door, of an automotive vehicle.
2. Description of the Prior Art
A door, such as a back door and a side door, of an automotive vehicle is provided with an outer door handle. The door is designed to be unlocked by operating this outer door handle,(e.g. see Japanese Utility Model Laid-Open No. 5-64368).
In the case of a back door, this type of outer door handle is typically arranged at a middle-height portion of the back door. The operation force of the outer door handle is transmitted to a door lock arranged at the lower end portion of the back door via a transmission mechanism such as a rod, so as to operate the door lock.
However, since such a conventional outer door handle structure is an indirect operation system which uses a transmission mechanism such as a rod between the outer door handle and the door lock, the number of parts is great so as to increase the weight and the assembly manday.
In addition, this type of outer door handle is long sideways so as to be easy to be manually operated. The outer door handle is pivotably supported on two arm portions. When the outer door handle is pulled so as to rotate the arm portions, an operating lever mounted on one of the arm portions is rotated to transmit the rotational stroke of the operating lever to the door lock so as to unlock the door. Therefore, when the outer door handle is operated, it is important that the operating lever rotates by at least a stroke quantity necessary to unlock the door, and the quantity of rotational stoke of the outer door handle is so set as to fulfill this condition.
Thus, in such a conventional outer door handle structure, the two arm portions are designed to have the same quantity of rotational stroke as the quantities of rotational stroke necessary for the arm portions. However, if the operator holds a portion neighboring one end portion of the outer door handle on the side of the other arm portion on which the operating lever is not mounted, the operating force applied to the outer door handle by the operator may be biased toward the end portion of the outer door handle on the side of the other arm portion, and the whole outer door handle may be deformed so as to be twisted. Therefore, although the other arm portion to which the operating force is directly applied by the operator's hand may surely rotate by a preset stroke quantity, the one arm portion on which the operating lever is mounted can not sufficiently rotate due to the twist of the whole outer door handle, so that the actual quantity of rotational stroke may be insufficient. For that reason, the operating lever can not sufficiently rotate, and in the case of the worst, the door can not be surely unlocked.
Therefore, in order to prevent the outer door handle from being deformed so as to be twisted, it is required to change the material of the outer door handle to a hard zinc die-cast or to increase the sectional area of the arm portion to increase the strength thereof, so that the weight and cost of the outer door handle are increased.
Alternatively, the quantities of rotational stroke of the arm portions may be set to be largish. That is, the quantities of rotational stroke of both arm portions are set to be sufficiently greater than the necessary quantities of rotational stroke so that one of the arm portions can rotate by the necessary quantity of rotational stroke even if the outer door handle is twisted. Thus, even if the one arm portion can not sufficiently rotate, it is possible to ensure the rotational stroke necessary to unlock the door. However, in this method, since the preset quantity of rotational stroke is great, the space occupied by the arm portions is increased to decrease the space for other parts inside of the door, so that it is difficult to design the door lock and other devices inside of the door.